A hierarchical nanolamella-structured alloy with excellent combinations of tensile properties

Dual phase (alpha+beta)-Ti alloys with a fully fine laminated microstructure usually exhibit a high strength but a limited ductility. In the present study, a hierarchical nanolaminated microstructure consisting of lamellae with nano- and submicrometer-sized widths has been produced in a TiZrAIV alloy by employing severe plastic deformation (SPD) combined with subsequent thermal annealing. The hierarchical nanolamella-structured Ti alloy exhibits excellent combinations of tensile properties, e.g., an ultimate tensile strength sigma(UTS)=1600 MPa and an elongation to failure epsilon(f)=6.5%. The high strength can be attributed to the formation of a lot of nanoscale alpha lamellae in the alloy, and the enhanced ductility results mainly from both the coarse alpha lamellae that have a high strain hardening capability and the complex strain paths caused by a hierarchical nanolaminated structure. (C) 2014 Elsevier B.V. All rights reserved.